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Research about Albany, Georgia

Source-linked reports with geographic coverage including Albany, Georgia.

16 recordsLinked to original sources
USGS2012

Hydrologic conditions, groundwater quality, and analysis of sink hole formation in the Albany area of Dougherty County, Georgia, 2009

The U.S. Geological Survey, in cooperation with the Albany Water, Gas, and Light Commission has conducted water resources investigations and monitored groundwater conditions and availability in the Albany, Georgia, area since 1977. This report presents an overview of hydrologic conditions, water quality, and groundwater studies in the Albany area of Dougherty County, Georgia, during 2009. Historical data also are presented for comparison with 2009 data. During 2009, groundwater-level data were collected in 29 wells in the Albany area to monitor water-level trends in the surficial, Upper Floridan, Claiborne, Clayton, and Providence aquifers. Groundwater-level data from 21 of the 29 wells indicated an increasing trend during 2008–09. Five wells show no trend due to lack of data and three wells have decreasing trends. Period-of-record water levels (period of record ranged between 1957–2009 and 2003–2009) declined slightly in 10 wells and increased slightly in 4 wells tapping the Upper Floridan aquifer; declined in 1 well and increased in 2 wells tapping the Claiborne aquifer; declined in 4 wells and increased in 2 wells tapping the Clayton aquifer; and increased in 1 well tapping the Providence aquifer. Analyses of groundwater samples collected during 2009 from 12 wells in the Upper Floridan aquifer in the vicinity of a well field located southwest of Albany indicate that overall concentrations of nitrate plus nitrite as nitrogen increased slightly from 2008 in 8 wells. A maximum concentration of 12.9 milligrams per liter was found in a groundwater sample from a well located upgradient from the well field. The distinct difference in chemical constituents of water samples collected from the Flint River and samples collected from wells located in the well-field area southwest of Albany indicates that little water exchange occurs between the Upper Floridan aquifer and Flint River where the river flows adjacent to, but downgradient of, the well field. Water-quality data collected during 2008 from two municipal wells located in northern Albany and downgradient from a hazardous waste site indicate low-level concentrations of pesticides in one of the wells; however, no pesticides were detected in samples collected during 2009. Detailed geologic cross sections were used to create a three-dimensional, hydrogeologic diagram of the well field southwest of Albany in order to examine the occurrence of subsurface features conducive to sinkhole formation. Monitored groundwater-level data were used to assess the possible relations between sinkhole formation, precipitation, and water levels in the Upper Floridan aquifer. Although the water levels in well 12L382 oscillated above and below the top of the aquifer on a regular basis between 2007 and 2009, sinkhole development did not appear to correlate directly with either well-field pumping or water levels in the Upper Floridan aquifer. Specifically, two sinkholes formed in each of the years 2003 and 2005 when water levels were almost 20 feet above the top of the aquifer during most of the year. Water-level and sinkhole-formation data continue to be collected to allow further study and analysis.

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USGS2008

Evaluation of floodplain modifications to reduce the effect of floods using a two-dimensional hydrodynamic model of the Flint River at Albany, Georgia

Potential flow characteristics of future flooding along a 4.8-mile reach of the Flint River in Albany, Georgia, were simulated using recent digital-elevation-model data and the U.S. Geological Survey finite-element surface-water modeling system for two-dimensional flow in the horizontal plane (FESWMS-2DH). The model was run at four water-surface altitudes at the Flint River at Albany streamgage (02352500): 181.5-foot (ft) altitude with a flow of 61,100 cubic feet per second (ft 3 /s), 184.5-ft altitude with a flow of 75,400 ft 3 /s, 187.5-ft altitude with a flow of 91,700 ft 3 /s, and 192.5-ft altitude with a flow of 123,000 ft 3 /s. The model was run to measure changes in inundated areas and water-surface altitudes for eight scenarios of possible modifications to the 4.8-mile reach on the Flint River. The eight scenarios include removing a human-made peninsula located downstream from Oglethorpe Boulevard, increasing the opening under the Oakridge Drive bridge, adding culverts to the east Oakridge Drive bridge approach, adding culverts to the east and west Oakridge Drive bridge approaches, adding an overflow across the oxbow north of Oakridge Drive, making the overflow into a channel, removing the Oakridge Drive bridge, and adding a combination of an oxbow overflow and culverts on both Oakridge Drive bridge approaches. The modeled inundation and water-surface altitude changes were mapped for use in evaluating the river modifications. The most effective scenario at reducing inundated area was the combination scenario. At the 187.5-ft altitude, the inundated area decreased from 4.24 square miles to 4.00 square miles. The remove-peninsula scenario was the least effective with a reduction in inundated area of less than 0.01 square miles. In all scenarios, the inundated area reduction increased with water-surface altitude, peaking at the 187.5-ft altitude. The inundated area reduction then decreased at the gage altitude of 192.5 ft.

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USGS2007

Two-Dimensional Flood-Inundation Model of the Flint River at Albany, Georgia

Potential flow characteristics of future flooding along a 4.8-mile reach of the Flint River in Albany, Georgia, were simulated using recent digital-elevation-model data and the U.S. Geological Survey finite-element surface-water modeling system for two-dimensional flow in the horizontal plane (FESWMS-2DH). Simulated inundated areas, in 1-foot (ft) increments, were created for water-surface altitudes at the Flint River at Albany streamgage (02352500) from 192.5-ft altitude with a flow of 123,000 cubic feet per second (ft3/s) to 179.5-ft altitude with a flow of 52,500 ft3/s. The model was calibrated to match actual floods during July 1994 and March 2005 and Federal Emergency Management Administration floodplain maps. Continuity checks of selected stream profiles indicate the area near the Oakridge Drive bridge had lower velocities than other areas of the Flint River, which contributed to a rise in the flood-surface profile. The modeled inundated areas were mapped onto monochrome orthophoto imagery for use in planning for future floods. As part of a cooperative effort, the U.S. Geological Survey, the City of Albany, and Dougherty County, Georgia, conducted this study.

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USGS2006

U.S. Geological Survey Georgia Water Science Center and Albany Water, Gas, and Light Commission Cooperative Water Program— Summary of activities, July 2005 through June 2006

The U.S. Geological Survey (USGS) has been working with the Albany Water, Gas, and Light Commission to monitor ground-water quality and availability since 1977. This report presents the findings for July 2005 through June 2006 and summarizes the ground-water and surface-water conditions for 2005. Water levels in 14 wells were continuously monitored in Dougherty County, Georgia. Water levels in 12 of those wells were above normal, one was normal, and one was below normal. Ground-water samples collected from the Upper Floridan aquifer indicate that nitrate levels have increased in 13 wells and decreased in two wells from a year earlier. A sample also was collected from the Flint River. A trilinear diagram showing the percent composition of selected major cations and anions indicates that the ground-water quality of the Upper Floridan aquifer at the Albany wellfield is distinctly different from the water quality of the Flint River. To improve the understanding of the ground-water flow system and nitrate movement in the Upper Floridan aquifer, the USGS is developing a ground-water flow model in the southwest Albany area, Georgia.

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USGS2005

Ground-water flow and water quality in the Upper Floridan aquifer, southwestern Albany area, Georgia, 1998-2001

During 1997, the Dougherty County Health Department sampled more than 700 wells completed in the Upper Floridan aquifer in Dougherty County, Georgia, and determined that nitrate as nitrogen (hereinafter called nitrate) concentrations were above 10 milligrams per liter (mg/L) in 12 percent of the wells. Ten mg/L is the Georgia primary drinking-water standard. The ground-water flow system is complex and poorly understood in this predominantly agricultural area. Therefore, the U.S. Geological Survey (USGS) - in cooperation with Albany Water, Gas and Light Commission - conducted a study to better define ground-water flow and water quality in the Upper Florida aquifer in the southwestern Albany area, Georgia. Ground-water levels were measured in the southwestern Albany area, Georgia, during May 1998 and March 1999 (spring), and October 1998 and September 1999 (fall). Groundwater levels measured in 75 wells open only to the Upper Floridan aquifer were used to construct potentiometric-surface maps for those four time periods. These maps show that ground water generally flows from northwest to southeast at gradients ranging from about 2 to greater than 10 feet per mile. During spring and fall 1998, ground-water levels were high and mounding of the potentiometric surface occurred in the central part of the study area, indicating a local recharge area. Water levels declined from December through February, and by March 1999 the mound in the potentiometric surface had dissipated. Of the 75 wells in the potentiometric network, 24 were selected for a water-quality network. These 24 wells and 1 spring were sampled during fall 1998 and spring 1999. Samples were analyzed for major chemical constituents, selected minor constituents, selected nutrients, and chlorofluorocarbons (CFC). Water-quality field measurements - such as water temperature, pH, specific conductance (SC), and dissolved oxygen (DO) - were taken at each well. During August 2000, a ground-water sample was collected and analyzed for selected sewage tracers. During March 2001, water samples from selected wells were analyzed for nitrogen and oxygen isotopes. Age-dating analysis using CFCs yield apparent groundwater ages that range from modern to greater than 50 years. The chemistry of ground water in the Upper Floridan aquifer varies widely throughout the southwestern Albany area, Georgia, and in general represents the chemistry commonly found in recharge areas. From fall 1998 through spring 1999, median values of pH, SC, and DO concentration were 7.6 standard units, 266 microsiemens per centimeter at 25 degrees Celsius (uS/cm), and 5.6 mg/L, respectively. The SC is highest (350 - 400 uS/cm) where mounding of the potentiometric surface exists. Specific DO concentrations indicate an area of anoxic ground water in the north-central part of the study area. Water samples indicate that ground water in the study area is dominated by calcium and bicarbonate ions, which is consistent with the limestone lithology of the aquifer. About 25 percent of the samples contained sodium and chloride at ratios similar to those in rainfall, indicating a close proximity to recharge areas. The remaining water samples, however, had sodiumchloride ratios less than 0.90, the ratio in Tift County, Georgia, rainfall samples. These low sodium-chloride ratios are consistent with chloride enrichment. Minor constituent and nutrient concentrations typically are below laboratory reporting limits; however, the maximum nitrate concentration measured during the study period was 12.2 mg/L, and the median concentration for the study period was 3.0 mg/L. Samples collected during 1999 had a higher median nitrate concentration than the 1998 samples. Regression analysis indicated that nitrate concentrations are related exponentially to chloride concentrations. Four distinct groups of ground-water-quality samples, plus four unique samples, were identified using cluster analysis. Water-quality groups I and

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USGS2002

Ground-water-quality data for Albany and surrounding areas, Southwest Georgia, 1951-99

This report presents ground-water-quality data from the surficial, Upper Floridan, Claiborne, Clayton, and Upper Cretaceous aquifers in the Albany and surrounding areas of southwest Georgia. Water-quality data from about 186 wells in Baker, Calhoun, Dougherty, Lee, Mitchell, Terrell, and Worth Counties are presented for the period from 1951 through 1999. The data include field water-quality parameters collected during 1951-99, volatile and semi-volatile organic compounds collected during 1981-97, inorganic compounds collected during 1951-99, trace metals collected during 1964-99, radiochemicals collected during 1993-95, herbicides and insecticides collected during 1980-97, and recovery data for laboratory surrogate compounds (used for quality control and quality assurance for organic samples) collected during 1993-97. Ground-water quality data are presented in tables by data type and arranged by well number. Illustrations in this report contain information about study area location, well location, stratigraphy, and formation water-bearing properties. Ground-water-quality data are presented in text files and in a data base that includes geographic and tabular data. Data presented in this report provide a base with which to better define and interpret the quality of ground water in Albany, Ga., and surrounding areas. Although some of these data may have been published in previous reports associated with water-resources investigations, water-quality data are compiled as a useful resource.

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USGS1999

Hydrogeology of the upper Floridan Aquifer in the vicinity of the Marine Corps Logistics Base near Albany, Georgia

In 1995, the U.S. Navy requested that the U.S. Geological Survey conduct an investigation to describe the hydrogeology of the Upper Floridan aquifer in the vicinity of the Marine Corps Logistics Base, southeast and adjacent to Albany, Georgia. The study area encompasses about 90 square miles in the Dougherty Plain District of the Coastal Plain physiographic province, in Dougherty and Worth Counties-the Marine Corps Logistics Base encompasses about 3,600 acres in the central part of the study area. The Upper Floridan aquifer is the shallowest, most widely used source of drinking water for domestic use in the Albany area. The hydrogeologic framework of this aquifer was delineated by description of the geologic and hydrogeologic units that compose the aquifer; evaluation of the lithologic and hydrologic heterogeneity of the aquifer; comparison of the geologic and hydrogeologic setting beneath the base with those of the surrounding area; and determination of ground-water-flow directions, and vertical hydraulic conductivities and gradients in the aquifer. The Upper Floridan aquifer is composed of the Suwannee Limestone and Ocala Limestone and is divided into an upper and lower water-bearing zone. The aquifer is confined below by the Lisbon Formation and is semi-confined above by a low-permeability clay layer in the undifferentiated overburden. The thickness of the aquifer ranges from about 165 feet in the northeastern part of the study area, to about 325 feet in the southeastern part of the study area. Based on slug tests conducted by a U.S. Navy contractor, the upper water-bearing zone has low horizontal hydraulic conductivity (0.0224 to 2.07 feet per day) and a low vertical hydraulic conductivity (0.0000227 to 0.510 feet per day); the lower water-bearing zone has a horizontal hydraulic conductivity that ranges from 0.0134 to 2.95 feet per day. Water-level hydrographs of continuously monitored wells on the Marine Corps Logistics Base show excellent correlation between ground-water level and stage of the Flint River. Ground-water-flow direction in the southwestern part of the base generally is southeast to northwest; whereas, in the northeastern part of the base, flow directions generally are east to west, as well as from west to east, thus creating a ground-water low. Ground-water flow in the larger study area generally is east to west towards the Flint River, with a major ground-water-flow path existing from the Pelham Escarpment to the Flint River and a seasonal cone of depression the size of which is dependent upon the magnitude of irrigation pumping during the summer months. Calculated vertical hydraulic gradients (based upon data from 11 well-cluster sites on the Marine Corps Logistics Base) range from 0.0016 to 0.1770 foot per foot, and generally are highest in the central and eastern parts of the base. The vertical gradient is downward at all well-cluster sites.

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USGS1999

Hydrogeology and water quality of the upper Floridan aquifer, western Albany area, Georgia

Geologic, hydrologic, and water-quality data were collected to refine the hydrogeologic framework conceptual model of the Upper Floridan aquifer, and to qualitatively evaluate the potential of human activities to impact water quality in the Upper Floridan aquifer in the western Albany area, Georgia. Ground-water age dating was conducted by using chlorofluorocarbons (CFC) and tritium concentrations in water from the Upper Floridan aquifer to determine if recharge and possible contaminant migration to the aquifer is recent or occurred prior to the introduction of CFCs and tritium in the early 1950's into the global natural water system. Data were collected from core holes and wells installed during this study and previously existing wells in the Albany area. Hydrogeologic data collected during this study compare well to the regional hydrogeologic conceptual model developed during previous studies. However, the greater data density available from this study shows the dynamic and local variability in the hydrologic character of the Upper Floridan aquifer in more detail. The occurrence of sediment sizes from clay to gravel in the overburden, the absence of overburden because of erosion or sinkhole collapse, and large areas lacking surface drainage west of the Flint River provide potential areas for recharge and contaminant migration from the surface to the Upper Floridan aquifer throughout the study area. Ground-water ages generally range from 9 to 34 years, indicating that recharge consisting of 'modern' water (post early-1950's) is present in the aquifer. Ground-water ages and hydraulic heads in the Upper Floridan aquifer have an irregular distribution, indicating that localized areas of recharge to the aquifer are present in the study area. Generally, water in the Upper Floridan aquifer is calcium-bicarbonate rich, having low concentrations of magnesium, potassium, sodium, chloride, and sulfate. Water in the Upper Floridan aquifer is oxygenated, having dissolved-oxygen concentrations greater than 2 milligrams per liter. Nitrite-plus-nitrate as nitrogen, is present in the aquifer at concentrations ranging from less than 0.02 to 5.5 milligrams per liter. Areas of higher nitrate concentrations in the aquifer, coupled with widely distributed localized recharge to the aquifer indicates that suburban residential and agricultural land use in the western Albany area may affect water quality in the Upper Floridan aquifer. However, concentrations exceeding drinking water criteria were not detected in the study area. Generally, water in the Upper Floridan aquifer is calcium-bicarbonate rich, having low concentrations of magnesium, potassium, sodium, chloride, and sulfate. Water in the Upper Floridan aquifer is oxygenated, having dissolved-oxygen concentrations greater than 2 milligrams per liter. Nitrite-plus-nitrate as nitrogen, is present in the aquifer at concentrations ranging from less than 0.02 to 5.5 milligrams per liter. Areas of higher nitrate concentrations in the aquifer, coupled with widely distributed localized recharge to the aquifer indicates that suburban residential and agricultural land use in the western Albany area may affect water quality in the Upper Floridan aquifer. However, concentrations exceeding drinking water criteria were not detected in the study area.

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USGS1997

Hydrogeologic evaluation of the Upper Floridan aquifer in the southwestern Albany area, Georgia

A cooperative study by the Albany Water, Gas, and Light Commission and the U.S. Geological Survey was conducted to evaluate the hydrogeology of the Upper Floridan aquifer in an area southwest of Albany and west of the Flint River in Dougherty County, Ga. The study area lies in the Dougherty Plain district of the Coastal Plain physiographic province. In this area, the Upper Floridan aquifer is comprised of the upper Eocene Ocala Limestone, confined below by the middle Eocene Lisbon Formation, and semiconfined above by the undifferentiated Quaternary overburden. The overburden ranges in thickness from about 30 to 50 feet and consists of fine to coarse quartz sand, clayey sand, sandy clay, and clay. The Upper Floridan aquifer has been subdivided into an upper water-bearing zone and a lower water-bearing zone based on differences in lithology and yield. In the study area, the upper water-bearing zone generally consists of dense, highly weathered limestone of low permeability and ranges in thickness from 40 to 80 feet. The lower water-bearing zone consists of hard, slightly weathered limestone that exhibits a high degree of secondary permeability that has developed along fractures and joints, and ranges in thickness from about 60 to 80 feet. Borehole geophysical logs and borehole video surveys indicate two areas of high permeability in the lower water-bearing zone-one near the top and one near the base of the zone. A wellfield consisting of one production well and five observation-well clusters (one deep, intermediate, and shallow well in each cluster) was constructed for this study. Spinner flowmeter tests were conducted in the production well between the depths of 110 and 140 feet below land surface to determine the relative percentages of water contributed by selected vertical intervals of the lower water-bearing zone. Pumping rates during these tests were 1,080, 2,200, and 3,400 gallons per minute. The results of these pumping tests show that the interval between 118 and 124 feet below land surface contributes a significant percentage of the total yield to the well. An aquifer test was conducted by pumping the production well at a constant rate of 3,300 gallons per minute for about 49 hours. Time-dependent water-level data were collected throughout the pumping and recovery phases of the test in the pumped well and the observation wells. The maximum measured drawdown in the observation wells was about 2.6 ft. At about 0.5 mile from the pumped well, there was little measurable effect from pumping. Water levels increased during the test in wells located within about 3.75 miles of the Flint River (about 0.5 miles east of the pumping well). This water-level increase correlated with a 3.5-feet increase in the stage of the Flint River. The hydraulic characteristics of the Upper Floridan aquifer were evaluated using the Hantush-Jacob curve-matching and Jacob straight-line methods. Using the Hantush-Jacob method, values for transmissivity ranged from about 120,000 to 506,000 feet squared per day; values for storage coefficient ranged from 1.4 x 10-4 to 6.3 x 10-4; and values for vertical hydraulic conductivity of the overlying sediments ranged from 4.9 to 6.8 feet per day. Geometric averages for these values of transmissivity, storage coefficient, and vertical hydraulic conductivity were calculated to be 248,000 feet squared per day, 2.7 x 10-4, and 5.5 feet per day, respectively. If a dual porosity aquifer model (fracture flow plus matrix flow) is assumed instead of leakage, and the Jacob straight-line method is used with late time-drawdown data, the calculated transmissivity of the fractures ranged from about 233,000 to 466,000 feet squared per day; and storage coefficient of the fractures plus the matrix ranged from 5.1 x 10-4 to 2.9 x 10-2.

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USGS1994

Effects of urban flood-detention reservoirs on peak discharges and flood frequencies, and simulation of flood-detention reservoir outflow hydrographs in two watersheds in Albany, Georgia

This report describes the effects of flood-detention reservoirs on downstream peak discharges of two urban tributaries to Kinchafoonee Creek (tributaries 1 and 2) in Albany, Georgia and presents simulated flood-detention reservoir outflow hydrographs. Rainfall-runoff data were collected for six years at two stations in these two urban watersheds. Tributary number 1 basin has a drainage area of 0.12 square miles, contains 23.8 percent impervious area, and contains two detention reservoirs. Tributary number 2 basin has a drainage area of 0.09 square miles, contains 12.9 percent impervious area, and has one detention reservoir. The Distributed Routing Rainfall-Runoff Model (DR3M) was calibrated using rainfall-runoff data collected during 1987- 92 at each station. DR3M was then used to simulate long-term (1906-33, 1941-73) peak discharges for these stations for conditions ranging from the existing condition with all detention reservoirs in place to the condition of no detention reservoirs. Flood-frequency relations based on the long-term peak discharges were developed for each simulation by fitting the logarithms of the annual peak discharge data to a Pearson type III distribution curve. The effect of detention reservoirs on peak discharge data to a Pearson type III distribution curve. The effect of detention reservoirs on peak discharges was determined by comparison of simulated flood-frequency peak discharges for conditions with and without the detention reservoirs. The comparisons indicated that the removal of flood-detention reservoirs from the tributary number 1 basin would increase the 10-, 50-, and 100-year peak discharges by 164 to 204 percent. Removal of the reservoir from tributary number 2 basin would increase these discharges by about 145 percent.

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USGS1993

Ground-water quality of the Upper Floridan Aquifer near an abandoned manufactured gas plant in Albany, Georgia

Manufactured gas plants produced gas for heating and lighting in the United States from as early as 1816 into the 1960's. By-products including, but not limited to, oil residues and tar, were generated during the gas-manufacturing process. Organic compounds (hydrocarbons) were detected in water in the upper water-bearing zone of the Upper Floridan aquifer near an abandoned manufactured gas plant (MGP) in Albany, Georgia, during an earlier investigation in 1990. Chemical analyses of ground-water samples collected from five existing monitoring wells in 1991 verify the presence of hydrocarbons and metals in the upper water-beating zone of the Upper Floridan aquifer. One well was drilled into the lower water-beating zone of the Upper Floridan aquifer in 1991 for water-quality sampling and water-level monitoring. Analyses of ground water sampled from this well did not show evidence of benzene, toluene, xylene, napthalene, acenaphthlene, or other related compounds detected in the upper water-bearing zone in the study area. Low concentrations of tetrachloroethane, trichloromethane, and l,2-cisdichloroethene were detected in a water sample from the deeper well; however, these compounds were not detected in the upper water-bearing zone in the study area. Inorganic constituent concentrations also were substantially lower in the deeper well. Overall, ground water sampled from the lower water-bearing zone had lower specific conductance and alkalinity; and lower concentrations of dissolved solids, iron, and manganese compared to ground water sampled from the upper water-bearing zone. Water levels for the upper and lower water-bearing zones were similar throughout the study period.

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USGS1993

Geohydrology and evaluation of water-resource potential of the upper Floridan Aquifer in the Albany area, southwestern Georgia

In the Albany area of southwestern Georgia, the Upper Floridan aquifer lies entirely within the Dougherty Plain district of the Coastal Plain physiographic province, and consists of the Ocala Limestone of late Eocene age. The aquifer is divided throughout most of the study area into an upper and a lower lithologic unit, which creates an upper and a lower water-bearing zone. The lower waterbearing zone consists of alternating layers of sandy limestone and medium-brown, recrystallized dolomitic limestone, and ranges in thickness from about 50 ft to 100 ft. It is highly fractured and exhibits well-developed permeability by solution features that are responsible for transmitting most of the ground water in the aquifer. Transmissivity of the lower water-bearing zone ranges from about 90,000 to 178,000 ft2/d. The upper water-bearing zone is a finely crystallized-to-oolitic, locally dolomitic limestone having an average thickness of about 60 ft. Transmissivities are considerably less in the upper water-bearing zone than in the lower water-bearing zone. The Upper Floridan aquifer is overlain by about 20-120 ft of undifferentiated overburden consisting of fine-to-coarse quartz sand and noncalcareous clay. A clay zone about 10-30 ft thick may be continuous throughout the southwestern part of the Albany area and, where present, causes confinement of the Upper Floridan aquifer and creates perched ground water after periods of heavy rainfall. The Upper Floridan aquifer is confined below by the Lisbon Formation, a mostly dolomitic limestone that contains trace amounts of glauconite. The Lisbon Formation is at least 50 ft thick in the study area and acts as an impermeable base to the Upper Floridan aquifer. The quality of ground water in the Upper Floridan aquifer is suitable for most uses; wells generally yield water of the hard, calcium-bicarbonate type that meets the U.S. Environmental Protection Agency's Primary or Secondary Drinking-Water Regulations. The water-resource potential of the Upper Floridan aquifer was evaluated by compiling results of drilling and aquifer testing in the study area, and by conducting computer simulations of the ground-water flow system under the seasonally low conditions of November 1985, and under conditions of pumping within a 12-mi 2 area located southwest of Albany. Results of test drilling, aquifer testing, and water-quality analyses indicate that, in the area southwest of Albany, geohydrologic conditions in the Upper Floridan aquifer, undifferentiated overburden, and Lisbon Formation were favorable for the aquifer to provide a large quantity of water without having adverse effects on the groundwater system. The confinement of the Upper Floridan aquifer by the undifferentiated overburden and the rural setting of the area of potential development decrease the likelihood that chemical constituents will enter the aquifer during development of the ground-water resources. Computer simulations of ground-water flow in the Upper Floridan aquifer, incorporating conditions for regional flow across model boundaries, leakage from rivers and other surface-water features, and vertical leakage from the undifferentiated overburden, were conducted by using a finite-element model for ground-water flow in two dimensions. Comparison of computed and measured water levels in the Upper Floridan aquifer for November 1985 at 74 locations indicated that computed water levels generally were within 5 ft of the measured values, which is the accuracy to which measured water levels were known. Water-level altitudes ranged from about 260 ft to 130 ft above sea level in the study area during calibration. Aquifer discharge to the Flint River downstream from the Lake Worth dam was computed by the calibrated model to be about 1 billion gallons per day; about 300 million gallons per day (Mgal/d) greater than was measured for similar lowflow conditions. T

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USGS1991

Geohydrology and evaluation of water-resource potential of the Upper Floridan aquifer in the Albany area, southwestern Georgia

In the Albany area of southwestern Georgia, the Upper Floridan aquifer lies entirely within the Dougherty Plain district of the Coastal Plain physiographic province, and consists of the Ocala Limestone of late Eocene age. The aquifer is divided throughout most of the study area into an upper and a lower lithologic unit, which creates an upper and a lower water-bearing zone. The lower water-bearing zone consists of alternating layers of sandy limestone and medium-brown, recrystallized dolomitic limestone, and ranges in thickness from about 50 to 100 feet. It is highly fractured, and exhibits well-developed permeability by solution features that are responsible for transmitting most of the ground water in the aquifer. Transmissivity of the lower water-bearing zone ranges from about 90,000 to 178,000 feet squared per day. The upper water-bearing zone is a finely crystallized-to-oolitic, locally dolomitic limestone having an average thickness of about 60 feet. Transmissivities in the upper water-bearing zone are considerably less than those in the lower water-bearing zone. The Upper Floridan aquifer is overlain by about 20 to 120 feet of undifferentiated overburden consisting of fine-to-coarse quartz sand and noncalcareous clay. A clay zone about 10 to 30 feet thick may be continuous throughout the southwestern part of the Albany area, and where present, causes confinement of the Upper Floridan aquifer and creates perched ground water after periods of heavy rainfall. The Upper Floridan aquifer is confined below by the Lisbon Formation, a mostly dolomitic limestone that contains trace amounts of glauconite. The Lisbon Formation is at least 50 feet thick in the study area, and acts as an impermeable base to the Upper Floridan aquifer. The quality of ground-water in the Upper Floridan aquifer is suitable for most uses; wells generally yield water of the hard, calcium-bicarbonate type that generally meets the U.S. Environmental Protection Agency's Primary or Secondary Drinking Water Regulations. The water-resource potential of the Upper Floridan aquifer was evaluated by compiling results of test drilling and aquifer testing in the study area, and by conducting computer simulations of the ground-water-flow system under the seasonal-low conditions of November 1985, and under conditions of pumping within a 12square-mile area located southwest of Albany. Results of test drilling, aquifer testing, and water-quality analyses indicate that, in the area southwest of Albany, geohydrologic conditions in the Upper Floridan aquifer, undifferentiated overburden, and Lisbon Formation were favorable for the aquifer to provide a large quantity of water without having adverse effects on the ground-water system. The confinement of the Upper Floridan aquifer by the undifferentiated overburden and the rural setting of the area of potential development decreases the likelihood that chemical constituents will enter the aquifer during development of the ground-water resources. Computer simulations of ground-water flow in the Upper Floridan aquifer, incorporating conditions for regional flow across model boundaries, leakage from rivers and other surface-water features, and vertical leakage from the undifferentiated overburden, were conducted by using a finite-element model for groundwater flow in two dimensions. Comparison of computed and measured water levels in the Upper Floridan aquifer for November 1985 at 74 locations indicated that computed water levels generally were within 5 feet of the measured values, which is the accuracy to which measured water levels were known. Water-level altitudes ranged from about 260 feet to 130 feet above sea level in the study area during calibration. Aquifer discharge to the Flint River downstream from the Lake Worth dam was computed by the calibrated model to be about 1 billion gallons per day; about 300 million gallons per day greater than was measured for similar low-flow conditions. The excess computed discharge was attributed partially to stream withdrawals for industrial use, non-reported use, and channel evaporation, but mostly to increased gradients and increased flow from the aquifer to the river than existed during calibration. Results from the calibrated finite-element model indicate that ground-water flow is dominated by inflow from regional-flow components to the west, north, and east of the study area, and by outflow to the Flint River downstream from the Lake Worth dam. Simulation results indicated that directions of ground-water flow were not changed appreciably by pumping at the November 1985 rates. However, vertical leakage from the undifferentiated overburden caused local deviations in the regional flow pattern. A sensitivity analysis that was performed on 18 hydrologic factors affecting the flow system in the Upper Floridan aquifer showed that computed water levels changed the most (were the most sensitive) in response to changes in hydraulic conductivity of the aquifer, vertical leakage coefficient and water level in the undifferentiated overburden, and stage of the Flint River downstream from the Lake Worth dam. Computed water levels were least sensitive to changes in well pumpage, flow across the northern boundary and from Lake Worth, the boundary coefficient for the Flint River downstream from the Lake Worth dam, and flow from Cooleewahee Creek. Simulations of six pumping scenarios in the area of potential development southwest of Albany showed that the Upper Floridan aquifer is capable of providing at least 72 million gallons per day from five locations (14.4 million gallons per day each) within this area without causing adverse affects on the flow system. The 72million-gallon-per-day scenario yielded a maximum drawdown of about 9.4 feet, which placed the water level in the Upper Floridan aquifer about 50 feet above the top of the lower water-bearing zone. Hence, the likelihood of aquifer dewatering, well interference, or sinkhole development from pumping as much as 72 million gallons per day from within the area of potential development is small. All pumping scenarios showed that about 81 percent of the ground-water pumpage was derived from regional flow that would have discharged to the Flint River downstream from the Lake Worth dam. The dominant ground-water-flow direction toward the Flint River was not changed and no induced recharge from the Flint River entered the potential-development area. Induced recharge from the undifferentiated overburden contributed to about 1.5 percent of the total volume pumped during the simulations.

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USGS1962

Geology of the Albany West quadrangle, Georgia

The Albany West Quadrangle is near the east edge of the Dougherty Plain of southwestern Georgia, an area of karst topography. The Ocala limestone (uppoer Eocene) underlies the quadrangle and crops out along the Flint River and its tributaries and sinkholes. Sinkholes of two ages are developed in the limestone. A gravelly argillaceous sand of Pliocene(?) age is exposed in ditches near the Flint River and in a sinkhole in the western part of the quadrangle. Reddish brown, argillaceous, older Pleistocene sand, believed to be part of a marine terrace deposit above altitude 160 feet, overlies the Pliocene(?) and is exposed in a sinkhole. River terraces are present along the Flint River at altitudes of 175 and 200 feet. Accumulations of dune sand east of the Flint River are believed to have been derived from the earliest river-terrace deposit. The quadrangle is covered by a mixture of reddish-brown, argillaceous, older Pleistocene sand, and residuum containing siliceous boulders from the Ocala limestone, which has been mapped as residuum.

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